The present invention relates to a method of controlling process variables in a fiberizing process and, in particular, to a method of controlling process variables in a rotary fiberizing process by monitoring the temperature of an external sidewall surface of a rotary fiberizing disk and an optical sensor assembly for monitoring the temperature of the external sidewall surface of the rotary fiberizing disk.
In the manufacture of fibers from high temperature, molten, clear or translucent, thermoplastic fiberizable materials, such as but not limited to the manufacture of glass fibers, it is normally desirable to produce fibers having selected physical characteristics, such as but not limited to a selected mean fiber diameter and/or a selected average fiber length, best suited for a particular application. For example, for reasons of manufacturing costs and required performance characteristics, the desired mean fiber diameter and/or average fiber length for a filtration product will normally differ from the desired mean fiber diameter and/or average fiber length of a building materials insulation product.
When manufacturing such fibers from a particular high temperature, molten, clear or translucent, thermoplastic fiberizable material by a fiberizing process that utilizes a rotating fiberizing disk of a specific diameter with a band of thousands of fiberizing orifices of a specific diameter in a peripheral sidewall of the fiberizing disk, the physical characteristics of the fibers produced by the fiberizing process can be changed by changing various process variables, such as but not limited to: the heating of the molten fiberizable material within the fiberizing disk to change the viscosity of the molten fiberizable material; the heating of the peripheral sidewall of the fiberizing disk to help maintain the molten fiberizable material at a preferred temperature and viscosity as the molten fiberizable material is being extruded through the fiberizing orifices in the sidewall of the fiberizing disk to form the fibers; the rate of rotation of the fiberizing disk; the heat input and velocity of high temperature products of combustion from an annular burner external of the rotating fiberizing disk; and the volume and velocity of an annular curtain air emitted from an annular air ring external of the rotating fiberizing disk.